Calking gun



Oct. 10, 1939. w. GRUND 2,175,601

CALKING GUN Filed Dec. 19, 1936 Patented Oct. 10, 1939 UNITED STATESPATENT OFFICE 4 Claims.

This invention relates to improvements in devices for discharging ordispensing plastic materials and more particularly to improvements incalking guns and devices of similar character.

The calking guns which have been employed heretofore for calking andpointing operations have been constructed primarily for dispensingrelatively light-bodied material. Where heavy bodied material,particularly that having an elastic and adhesive constituency, was used,the calking guns were either too weak in construction or assembly tofunction efliciently or required a considerable amount of efiort on thepart of the operator to actuate the guns.

An important object of this invention is to provide a calking gun whichis particularly adaptable for discharging heavy bodied elastic andadhesive calking compounds. A further object of this invention is toprovide such a gun which is capable of exerting a relatively highpressure upon the calking compound and which is of such a constructionas to withstand continuous operation at high pressures for long periodsof time. A meritorious feature of the invention is the case which thegun may be operated and at the same time exert a powerful force upon thecalking compound contained therein. All these features are combined intoa calking gun which is sturdy in construction and simple in assembly andoperation.

More specifically, the invention comprehends a type of calking gunhaving a tubular body for containing the calking compounds and a pistontherein for discharging the compound in controllable quantities from oneend of the body. Operating mechanism for advancing the piston is locatedadjacent to the opposite end of the tubular body. This mechanismincludes a pivoted lever, a pawl pivoted to the lever, and a rack andpinion assembly constructed in a novel way to multiply the action of thelever. In the embodiment of the invention described herein, the lever isarranged to rotate a relatively large wheel which in turn is adapted torotate a relatively small pinion having operative connections with apiston rod. In addition to these features there is a novel provision foryieldably retracting both the pawl and the operating lever to anoperating or released position. This last provision comprises a springwhich by reason of its novel connection to the pawl acts to swing boththe pawl and the lever to their initial operating positions.

The operating mechanism of the calking gun is disposed within a novelhandle structure attached to the rear end of the gun, This handlestructure is formed of one piece which in the embodirnent of theinvention disclosed herein may be cast into the form shown in thedrawing. The handle structure is adapted to fit into the rear end of thetube or cylinder in which the calking 5 compound is contained and novelprovision is made for securing the handle structure in fixed position tothe cylinder. As shown in the drawing, the rear end of the cylinder maybe provided with a longitudinal slot through which the handle 10structure may protrude.

Other objects, advantages, and meritorious features of the inventionwill become more apparent from the following specification, appendedclaims, and accompanying drawingwherein: 15

Figure 1 is a side view of the calking gun partially broken away todisclose the operating head of the piston,

Figure 2 is a detailed view of the operating mechanism showing thedetent for preventing 2 return movement of the piston,

Figure 3 is a view of the operating mechanism showing thelever-operating mechanism for advancing the piston in the cylinder,

Figure 4 is a cross sectional view along line 25 4-4 of Figure 3,

Figure 5 is a detailed view of the operating mechanism showing a mannerof releasing the detent.

Referring to the drawing, reference numeral 30 I0 indicates a tubularchamber or cylinder in which the calking compound or other material iscontained. A piston l2 reciprocates longitudinally in this cylinder andis adapted to discharge a calking compound through an opening in the 35tapered cap H which is threaded to one end of the cylinder. The pistonI2 is provided with a racked piston rod l6 which extends rearwardly fromthe piston and protrudes through the rear end of the cylinder. Thepiston rod is provided 40 with any suitable handle such as thatindicated at I8 for retracting the same and the piston connectedthereto. It is readily apparent that the cylinder is filled with calkingcompound by re- 5 moving the cap I! and introducing compound 4 into theforward end of the cylinder.

The operating mechanism for advancing the piston against the calkingcompound in the cylinder is contained within the handle structure 20 50in the manner shown in Figure 3. The operating mechanism includes anoperating lever 22. A pin 24 forms the axis about which the lever ispivoted. Forward swinging movement of the lever is limited by a stopelement 26 shown in Figure One end of the pawl 28 is tapered forengage-- ment with a ratchet wheel 32 and it is obvious from Figure 2that upward movement of the pawl will rotate the ratchet wheelcounterclockwise, this being the only effective movement is can impartto the ratchet wheel. The ratchet wheel is associated with a pinion 34in any suitable way for Joint rotation about the axis of a pin I. Pinionll engages with the rack bar it as shown in Figure 3 and it is apparentthat upon counterclockwise rotation thereof it will advance the rack barand piston i2 associated therewith and exert a pressure upon the calkingcompound in the cylinder. As shown in Figure 3 the ratchet wheel '32 isof larger diameter than the pinion and this.

variation in size assists in multiplying the movement of the lever 22.

' The end of the pawl 28 opposite the ratchet wheel is provided with astud 38 to which a coil spring 40 is connected. The opposite end of thecoil spring is secured in any suitable way to a stationary part of thehandle structure remote from the operating mechanism. The coil spring 40is normally tensioned and exerts a downward pressure upon the lower endof the pawl 28. As shown in Figure 3 the coil spring I is at a slightinclination to the vertical and this relationship tends to swing thetapered end of the pawl into engagement with the ratchet wheel 32. Thedownward pull exerted by the coil spring 40 acts through the pivotalconnection of the pawl to the lever 22 to swing the lever forwardly intoreleased or inoperative position. The coil spring 40, therefore,accomplishes the dual function of yieldably engaging the pawl with theratchet wheel 32 and yieldably disposing the lever 22 in inoperativeposition. The dual function of this spring eliminates the necessity ofanother spring to accomplish either one of these functions.

Pivoted to a pin 44 is a detent or dog 48 having a pointed extremityengageable with the teeth of the ratchet wheel. The detent l is normallypressed into engagement with the ratchet wheel by any suitable springmechanism such as a spring wire ll shown in Figure 2. Actuatingmechanism for swinging the detent to a released position against thetension of the wire spring 48 comprises an arm I! pivotally connected tothe pointed extremity of the detent. As shown in Figures 2 and 3, arm 50extends rearwardly of the handle structure and protrudes through anaperture in the rear of the handle structure. The rear end of the arm 50is notched at 52 for a relatively short distance and, as shown in Figure2, this notched construction is adapted to engage with the wall of thehandle structure. When the arm 50 assumes this position shown in Figure2, the detent it is swung free of the teeth on the ratchet wheel and thelatter may be rotated clockwise. When the arm ill assumes the positionin Figure 3, the detent is yieldably pressed into engagement with theteeth on the ratchet wheel and clockwise rotation of the ratchet wheelis therebyprevented.

The handle structure 2|! is preferably formed of a single piece of metalcast into the desired formation. The handle structure is slottedthroughout its extent to provide a pair of spaced walls 54 shown inFigure 4. These spaced walls extend the full length of the handlestructure and are joined together only along the rear of the handle asis clearly apparent in Figure 3.

The walls 44 are provided on their outside surfaces with a pair ofcomplementary circular flanges II and I8. These circularflanges aresubstantially the same diameter as the interior wall of cylinder II.when the handle structure is inserted into the cylinder II, the circularflanges I. and II enter the cylinder and their peripheries bear againstthe inner wall of the cylinder. This relationship is clearly apparent inFigure 4. In order that the lowermost portions of the handle structuremay extend perpendicularly from the side of cylinder il a longitudinalslot is provided on the under part of cylinder ll adjacent the rear endthereof. This slot is of substantially the same width as the outsidedimensions of the walls "-54. This assembly is likewise clearly shown inFigure 4.

It is clearly apparent that except for the actuating arm ill and thespring wire 4|, all the operating mechanism is located in the spacewithin the walls 54-. As shown in Figure 4, the rack bar I extendsbetween the walls -54 and between the pinion I4 and a roller which isJournaled about the pin 44. This provides a bearing for the rack bar andenables it to ride through the handle structure with less friction.

To operate the mechanism, the handle structure is grasped by one hand ofthe operator and pressure exerted to swing the lever rearwardly towardthe fixed part of the handle. This movement will swing the pawl 28upwardly against the tension of the coil spring 40 and by reason of theengagement between the pawl and the ratchet wheel the latter will berotated in a counterclockwise rotation. Rotation of the ratchet wheelwill impart rotation to the pinion I4 and the latter will advance therack bar and the piston associated therewith in the cylinder. When theoperator releases the pressure on the lever 22, it will swing forwardlyto released position because of the force applied thereto by the coilspring 40. The return movement of the lever will lower the pawl to a newposition on the ratchet wheel. During the forward advance of the rackbar It, the detent 40 is in continuous engagement with the teeth on theratchet wheel and as soon as the latter stops rotating, the detentfunctions to prevent return rotation. In order to retract the rack barand the piston associated therewith for filling purposes, the arm 8| isbodily shifted until the notch 52 interlocks with the end wall of thehandle structure. Upon movement of the arm ii to this position, thedetent It will be free of the teeth on the ratchet wheel and clockwiserotation of the ratchet and the pinion associated therewith can beeffected. The rack bar is now free for retractable movement.

1 claim:

1. A calking gun comprising, in combination, a cylinder having a slot inthe'bottom rear end thereof, a piston in the cylinder having anoperating rod extending rearwardly thereof above and beyond said slot,an integral handle structure for the gun comprising an external handgrasping part and a part positioned inside of the rear end of thecylinder, said last mentioned part comprising spaced walls extendingvertically through the slot in the cylinder and forming a chamber in thespace between the walls adapted to house mechanism for operating the rodand through which the operating rod of the piston extends, said spacedwalls extending upwardly through the slot in the cylinder into contactwith the inner top side of the cylinder and having on their oppositesides a pair of spaced complementary circular flanges of substantiallythe same diameter as the inner wall of the cylinder apertured to receivesaid rod, the peripheral edges of said flanges bearing against the innerwall of the cylinder and acting in combination with the slot throughwhich the spaced walls extend to securely hold the handle structure tothe cylinder of the gun.

2. A calking gun comprising, in combination, a cylinder having a slot inthe bottom rear end thereof, an integral handle structure separatelyconstructed and assembled on the rear end of the cylinder, said handlestructure comprising an external hand grasping part and a partpositioned inside of the rear end of the cylinder, said last mentionedpart comprising spaced walls extending in parallel relationship throughthe slot in the rear end of the cylinder, said walls provided with meansprojecting laterally from opposite sides thereof into engagement withthe inner surfaces of the cylinder to hold the same against movementtherewithin.

3. A calking gun comprising, in combination, a cylinder opening outthrough the rear end and provided with a slot in the bottom rear endalso opening out through the rear end of the cylinder, a handlestructure for the gun comprising two spaced parallel walls whose outsidetransverse dimensions are equal to the width of the slot, said wallsforming on the outside of the cylinder an external hand grasping partand on the inside of the cylinder a housing for operating mechanism,said handle structure being insertable into and removable from the gunby slidable movement through the openend of the slot in the rear end ofthe cylinder.

4. A calking gun comprising, in combination, a cylinder open at its rearend and provided with a longitudinal slot in the bottom adjacent totherear end thereof and opening out through the rear end, and a handlestructure having a portion slidable into the'cylinder through the openrear end thereof and another portion forming an external hand graspingmeans, and an intermediate part of said handle structure connecting saidinternal cylinder fitting portion and said external hand graspingportion and being of a size to slide lengthwise into said slot when thehandle structure is assembled on the cylinder.

WILLIAM GRUND.

